PG&E commissions remote grid in Mariposa County

FILE - In this Oct. 10, 2019, file photo, a Pacific Gas and Electric sign sits in the exterior of a PG&E building in San Francisco. California power regulators are weighing a recommendation to back off plans to fine PG&E an additional $462 million for igniting a series of Northern California 2018 deadly wildfires rather than risk that the harsher punishment will scuttle the utility's plan to emerge from bankruptcy protection. The state's Public Utilities Commission is mulling whether to pare the penalties PG&E faces as the result of a proposed revision floated by one of agency's five commissioners, Clifford Rechtschaffen. The document was made public Monday, March 30, 2020.

Pacific Gas and Electric Company (PG&E) on June 7 marked the commissioning of its first hybrid renewable standalone power system, built and installed by BoxPower Inc. The remote grid, which permanently replaces the overhead distribution powerlines that once served a handful of customers in the Briceburg community, a High Fire-Threat District (HFTD) area of the Sierra Nevada foothills outside Yosemite National Park, improves reliability and significantly reduces wildfire risk.

PG&E’s 2021 Wildfire Mitigation Plan details a stand-alone power system as a new approach to utility service. The Briceburg system is the utility’s first such installation. It uses solar combined with battery energy storage and backup propane generation. It provides permanent energy supply to remote customers as an alternative to hardened poles and wires.

The approach has potential use in other PG&E service areas where isolated pockets of remote customers are served via long electric distribution lines that in many cases traverse through HFTD areas. Replacing these long distribution lines with a reliable and low-carbon local energy source is an innovative option that has now become feasible.

“PG&E is eager to deliver the benefits of remote grids to our customers, and we intend to expand the use of stand-alone power systems as an alternative to certain existing distribution lines, providing enhanced reliability with a lower risk profile and at a lower total cost,” said Jason Glickman, PG&E’s Executive Vice President, Engineering, Planning and Strategy.

In Mariposa County, five customer sites lost power in the Briceburg Fire of 2019 when the line serving them was destroyed. The historical line route is challenging to rebuild through the last 1.4 miles of rugged, HFTD terrain. Since then, PG&E has provided temporary generation to meet local customer power needs.

The commissioning of this new decentralized stand-alone power system represents PG&E’s transition to a hybrid renewable solution. This option will reliably repower these customers without the need to rebuild the overhead line, and the remote grid is intended to meet customer needs at lower lifetime costs and a significantly lower fire risk.

This Briceburg system is owned by PG&E and designed, installed, and maintained under contract to PG&E by BoxPower. The remote grid serves two residences, a visitor center, and telecommunications and transportation facilities.

The containerized microgrid system provides up to 89 percent renewable energy annually and an auxiliary ground-mounted solar array with a total nominal photovoltaic (PV) capacity of 36.5 kW DC. In addition to the PV array, the system includes a 27.2 kW / 68.4 kWh lithium ferro phosphate battery energy storage system that was prefabricated at the BoxPower facility in Grass Valley, Calif., before being transported to the site. The system also includes two integrated 35 kW propane generators for backup power, and a fire suppression system to protect the hardware and facility. The system is designed for rapid deployment and scalability, streamlining future replication at similar sites.

Testing initially took place in BoxPower’s Grass Valley facility, and subsequently on-site in Briceburg with assistance from PG&E, Underwriters Laboratories (UL), and Generac representatives.

PG&E and BoxPower can monitor and control the system via satellite and cellular connectivity, with capabilities for remote performance management, safety diagnostics, alarms, reporting, and automated refueling notifications.

“BoxPower is proud to play an important role in bringing clean, reliable, and fire-safe power to rural energy consumers through our work with PG&E and other utility companies,” said Angelo Campus, BoxPower’s Chief Executive Officer. “PG&E is leading the industry shift in California in terms of using remote grids specifically for wildfire mitigation purposes. PG&E’s example is one that other utilities in the state and across the West may be eager to follow in the face of worsening drought and extreme wildfire conditions.”

The Briceburg system along with other initial projects will enable PG&E to determine an appropriate expansion of remote grids using standalone power systems to support wildfire mitigation efforts. The utility has identified hundreds of potential locations for remote grids and is targeting up to 20 operational remote grid sites by the end of 2022. Additional remote grid sites, including El Dorado, Mariposa, Tulare, and Tehama counties, are currently being assessed across HFTDs in PG&E’s service area.

PG&E is a combined natural gas and electric utility serving more than 16 million people across 70,000 square miles in Northern and Central California.

BoxPower provides turnkey engineering, construction, and management services to rural consumers looking for clean, reliable, and affordable energy.

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The Clarion Energy Content Team is made up of editors from various publications, including POWERGRID International, Power Engineering, Renewable Energy World, Hydro Review, Smart Energy International, and Power Engineering International. Contact the content lead for this publication at

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